Improvement in reciprocating steam-engines



fR. G. NICLL & E. H. HULLMAN'N.

Reciprucating Steam Engines.

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ggwutnrz www UNITED STATEs PATENT (DEETGEo 7 rROBERT G. NIGOLL AND GERHARD H. HOLLMANN, OF HAZLEHURST, MISS.

IMPROVEMENT IN RECIPROCATING STEAM-ENGINES.

Specification forming part of Letters Patent No.

139,258, dated May 27, 1873; application led July 27, 1872.

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Figure 1 is a side elevation of our improved engine. Fig. 2 is a longitudinal sectional eleva-tion through the cylinder and valve-chest taken on the line w a; of Fig. 3, and Fig. 3 is a transverse section through the steam-chest.

Similar letters of reference indicate correspondin g parts.

A represents the valve-chest with ports opening through the bottom into the engine, adapted for lift or clack valves with brasslined seats. B represents the said lift-valves having a stem, C, extending up through stuff- 1 ing-boxes D in the top of the steam-chest, and connected to the rocking lever E on opposite sides of and equidistant from its pivot F, said stems being connected to said lever by screwing into the pendent nuts Gr so that they can be readily adjusted in respect. of their lift77 `Each valve has a blunt-tapered steel pin extending from the under side through the port below the surface of the cylinder to be acted on by the piston for shifting the valves by lifting one and depressing the other, the said piston being provided with steelfaced inclines I for so actuating them. These valves are like an ordinary three-wing valve, except on the bottoms they are carefully rounded off to the junction with the steel plugs that extend through the ports below the seating. Below the valve-seats the metal is cut out so Vthat the steam-branches off both sides as it enters the cylinder. The plugs H are formed with a flat head, L, to rest on the bottom of the seating, while the valves are also seated above. The piston is provided with an exhaust-chamber, M, with exhaust-ports N entering it from each side of the piston, anda hollow piston-rod, O, extending through a stuffing-box, P, in one of the cylinder-heads. The ports are provided with double-headed valves Q, Whose stems are a little longer than the distance through the piston so that the valves project a short distance beyond be closed by the said projecting ends coming against the cylinder-heads just before the piston stops and at the same time that it opens the valve B above.

By these arrangements we avoid the use of expensive valve gear, and we have valves which open to the full extent very suddenly, thus effectin g the changes quickly, and we avoid the friction of sliding valves. The motion of the engine is reversed by reversing the valves by hand when the steam is shut oli'. The valves remain in the positions to which they arek shifted by the pressure of the steam on the one covering the exhausting end of the engine. 1

Having claim as new and desire to secure by Letters Patent- Y 1. A steam-valve provided with bearing on top of seat, and plug H. having dat head L resting on the bottom thereof, as described.

2. A cylinder having lift-valves B B to admit steam, combined with' a piston having means M N Q for exhausting steam, as described.

- ROBERT G. NIGOLL.

GERHARD H. HOLLMANN.

Witnesses: i.

CHARLES BAAs, FRITZ VITZTHUM,

W. A. STONE.

the` piston when opened; also, so that they will' thus described our invention, we j 

